metasploit-framework/lib/net/ssh/test/packet.rb

81 lines
3.4 KiB
Ruby

require 'net/ssh/connection/constants'
require 'net/ssh/transport/constants'
module Net; module SSH; module Test
# This is an abstract class, not to be instantiated directly, subclassed by
# Net::SSH::Test::LocalPacket and Net::SSH::Test::RemotePacket. It implements
# functionality common to those subclasses.
#
# These packets are not true packets, in that they don't represent what was
# actually sent between the hosst; rather, they represent what was expected
# to be sent, as dictated by the script (Net::SSH::Test::Script). Thus,
# though they are defined with data elements, these data elements are used
# to either validate data that was sent by the local host (Net::SSH::Test::LocalPacket)
# or to mimic the sending of data by the remote host (Net::SSH::Test::RemotePacket).
class Packet
include Net::SSH::Transport::Constants
include Net::SSH::Connection::Constants
# Ceate a new packet of the given +type+, and with +args+ being a list of
# data elements in the order expected for packets of the given +type+
# (see #types).
def initialize(type, *args)
@type = self.class.const_get(type.to_s.upcase)
@data = args
end
# The default for +remote?+ is false. Subclasses should override as necessary.
def remote?
false
end
# The default for +local?+ is false. Subclasses should override as necessary.
def local?
false
end
# Instantiates the packets data elements. When the packet was first defined,
# some elements may not have been fully realized, and were described as
# Proc objects rather than atomic types. This invokes those Proc objects
# and replaces them with their returned values. This allows for values
# like Net::SSH::Test::Channel#remote_id to be used in scripts before
# the remote_id is known (since it is only known after a channel has been
# confirmed open).
def instantiate!
@data.map! { |i| i.respond_to?(:call) ? i.call : i }
end
# Returns an array of symbols describing the data elements for packets of
# the same type as this packet. These types are used to either validate
# sent packets (Net::SSH::Test::LocalPacket) or build received packets
# (Net::SSH::Test::RemotePacket).
#
# Not all packet types are defined here. As new packet types are required
# (e.g., a unit test needs to test that the remote host sent a packet that
# is not implemented here), the description of that packet should be
# added. Unsupported packet types will otherwise raise an exception.
def types
@types ||= case @type
when KEXINIT then
[:long, :long, :long, :long,
:string, :string, :string, :string, :string, :string, :string, :string, :string, :string,
:bool]
when NEWKEYS then []
when CHANNEL_OPEN then [:string, :long, :long, :long]
when CHANNEL_OPEN_CONFIRMATION then [:long, :long, :long, :long]
when CHANNEL_DATA then [:long, :string]
when CHANNEL_EOF, CHANNEL_CLOSE, CHANNEL_SUCCESS, CHANNEL_FAILURE then [:long]
when CHANNEL_REQUEST
parts = [:long, :string, :bool]
case @data[1]
when "exec", "subsystem" then parts << :string
when "exit-status" then parts << :long
else raise "don't know what to do about #{@data[1]} channel request"
end
else raise "don't know how to parse packet type #{@type}"
end
end
end
end; end; end